Warn when certain constructor is used

[Maurizio Cimadamore]

Try to call

https://docs.oracle.com/javase/7/docs/jdk/api/javac/tree/com/sun/source/util/Trees.html#getElement(com.sun.source.util.TreePath)

This should trigger attribution of the tree and give you the 'symbol' 
associated with the constructor. From there you can access the symbol 
signature using

https://docs.oracle.com/javase/7/docs/api/javax/lang/model/element/Element.html#asType()

And downcasting to this:

https://docs.oracle.com/javase/7/docs/api/javax/lang/model/type/ExecutableType.html

If this works, good, otherwise the solution would be more cumbersome - 
and it will involve setting up a task listener. But try this first.

Maurizio


On 31/05/18 13:19, Pietro Paolini wrote:
> Hi Maurizio,
>
> Thanks a lot. I would have an additional, and hopefully last, question.
>
> I am getting the NewClassTree which seems to provide me access to the - forgive me the coarse wording of it -  the "token", namely the textual representation
> of it, while I am mainly interested in the type.
>
> I am getting around it by comparing strings but I wonder if there is any way to get to the type of the expression :
>
> := new identifier ( arguments )
>
> What I have in my mind is to detect all instances in which the identifier has *type* A and the argument's  list is composed by a single *type* , let say B. That allows me to
> print something:
>
> "Hey, constructor new A(B) has been detected"
>
> Thanks a lot for your help so far, really.
>
> Thanks,
> P.
>
>
>
>
>
>> -----Original Message-----
>> From: Maurizio Cimadamore [mailto:maurizio.cimadamore at oracle.com]
>> Sent: 31 May 2018 12:45
>> To: Pietro Paolini
>> Cc: compiler-dev at openjdk.java.net
>> Subject: Re: Warn when certain constructor is used
>>
>>
>>
>> On 31/05/18 12:21, Pietro Paolini wrote:
>>> JCTree tree = (JCTree) trees.getTree(element);
>>> tree.accept(new LocalDateUtilDate());
>> There re two visitor methods in JCTree, one internal (used by javac),
>> one external (used by the API). I don't think you need to cast down to
>> JCTree (yet, at least). Just keep it as a com.sun.source.tree.Tree, and
>> you will see that the only 'accept' method there takes two arguments: a
>> visitor (which you have) and a visitor parameter; since you don't seem
>> to need a visitor parameter, you can just pass 'null' as second parameter.
>>
>> Maurizio